Fix async getter with => syntax

runtime/vm/parser.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/parser.h"
 
 #include "lib/invocation_mirror.h"
 #include "platform/utils.h"
 #include "vm/ast_transformer.h"
 #include "vm/bootstrap.h"
@@ skipping 5512 matching lines @@
   intptr_t accessor_end_pos = accessor_pos;
   bool is_native = false;
   if (is_external) {
     accessor_end_pos = TokenPos();
     ExpectSemicolon();
   } else if (CurrentToken() == Token::kLBRACE) {
     SkipBlock();
     accessor_end_pos = TokenPos();
     ExpectToken(Token::kRBRACE);
   } else if (CurrentToken() == Token::kARROW) {
+    if (is_getter && ((func_modifier & RawFunction::kGeneratorBit) != 0)) {
+      ReportError(modifier_pos,
+                  "=> style getter may not be sync* or async* generator");
+    }
     ConsumeToken();
+    BoolScope allow_await(&this->await_is_keyword_,
+                          func_modifier != RawFunction::kNoModifier);
     SkipExpr();
     accessor_end_pos = TokenPos();
     ExpectSemicolon();
   } else if (IsLiteral("native")) {
     ParseNativeDeclaration();
     accessor_end_pos = TokenPos();
     ExpectSemicolon();
     is_native = true;
   } else {
     ReportError("function block expected");
@@ skipping 7658 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart